The overall goal of this research is to quantitatively evaluate gene expression during oogenesis and early embryogenesis in the mouse. Specific examples of differential gene expression during mammalian oogenesis and early embryogenesis will be identified, their molecular basis determined, and their biological implications investigated. The immediate goals of this research are: 1. To determine whether or not the changes in protein synthesis seen during oocyte growth, meiotic maturation, and early embryogenesis correlate with changes in levels of transcription and types of transcripts during the same developmental periods. 2. To determine the absolute rates of synthesis, modification, and secretion of zona pellucida proteins during oocyte growth. 3. To identify additional specific biochemical markers of oocyte growth which can be used to critically evaluate growth of mouse oocytes in vitro.